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Citation for the original published paper (version of record):
Hassan, O., Ahlm, C., Evander, M. (2014)
A need for One Health approach - lessons learned from outbreaks of Rift Valley fever in Saudi
Arabia and Sudan..
Infection ecology & epidemiology, 4
http://dx.doi.org/10.3402/iee.v4.20710
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A need for One Health approach � lessonslearned from outbreaks of Rift Valleyfever in Saudi Arabia and Sudan
Osama Ahmed Hassan, BSc, MSc1,2,3, Clas Ahlm, MD, PhD2
and Magnus Evander, PhD3*1Department of Epidemiology and Diseases Control, Public Health Institute, Federal Ministry of Health,Khartoum, Sudan; 2Department of Clinical Microbiology, Infectious Diseases, Umea University, Umea,Sweden; 3Department of Clinical Microbiology, Virology, Umea University, Umea, Sweden
Introduction: Rift Valley fever (RVF) is an emerging viral zoonosis that impacts human and animal health.
It is transmitted from animals to humans directly through exposure to blood, body fluids, or tissues of infected
animals or via mosquito bites. The disease is endemic to Africa but has recently spread to Saudi Arabia and
Yemen. Our aim was to compare two major outbreaks of RVF in Saudi Arabia (2000) and Sudan (2007) from
a One Health perspective.
Methods: Using the terms ‘Saudi Arabia’, ‘Sudan’, and ‘RVF’, articles were identified by searching PubMed,
Google Scholar, and web pages of international organizations as well as local sources in Saudi Arabia and
Sudan.
Results: The outbreak in Saudi Arabia caused 883 human cases, with a case fatality rate of 14% and more
than 40,000 dead sheep and goats. In Sudan, 698 human cases of RVF were recognized (case fatality, 31.5%),
but no records of affected animals were available. The ecology and environment of the affected areas were
similar with irrigation canals and excessive rains providing an attractive habitat for mosquito vectors to
multiply. The outbreaks resulted in livestock trade bans leading to a vast economic impact on the animal
market in the two countries. The surveillance system in Sudan showed a lack of data management and
communication between the regional and federal health authorities, while in Saudi Arabia which is the
stronger economy, better capacity and contingency plans resulted in efficient countermeasures. Studies of the
epidemiology and vectors were also performed in Saudi Arabia, while in Sudan these issues were only partly
studied.
Conclusion: We conclude that a One Health approach is the best option to mitigate outbreaks of RVF.
Collaboration between veterinary, health, and environmental authorities both on national and regional levels
is needed.
Keywords: Rift Valley fever; Saudi Arabia; Sudan; One Health; outbreak; climate; mosquito; trade ban
Received: 26 February 2013; Revised: 30 September 2013; Accepted: 20 December 2013; Published: 4 February 2014
The emerging Rift Valley fever (RVF) is a trans-
boundary zoonotic disease, transmitted to animals
and humans via mosquito bites, but also directly
through exposure to blood, body fluids, or tissues of
infected animals (1). It is caused by RVF virus (RVFV)
belonging to the Bunyaviridae family, genus Phlebovirus,
which is endemic in many African countries, and also
since 2000 in the Arabian Peninsula where Saudi Arabia
and Yemen have been affected (2, 3). The RVFV usually
causes outbreaks after floods when the conditions are
favorable for virus transmission via mosquitoes (4). There
is great concern that the disease will continue to spread
to new regions around the world, such as South-East
Asia, Americas, and Europe with potentially devastating
consequences (5�7). The increased animal trade and the
possibility of vectors transported aerially as well as
climate change could increase the risk for the disease to
expand further (8�10).
RVFV infection of livestock causes abortions and high
perinatal mortality (�95%) in herds of sheep, goats,
cattle, and camels. These animals are important not only
for meat production but also for dairy production and
trade. Outbreaks devastate the local economy, result in
export embargoes, and contribute to poverty in many
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�CASE STUDY
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Citation: Infection Ecology and Epidemiology 2014, 4: 20710 - http://dx.doi.org/10.3402/iee.v4.20710
regions of the affected countries. Human infection may
be severe and historically the disease has had a case
fatality rate in humans of 1% (11), but in recent out-
breaks rates of 14�31% have been reported (12�14).
Hepatorenal failure and hemorrhagic, ocular, and enceph-
alitic complications were found in severe cases (12, 15, 16).
The putative increase of severity and the recent geogra-
phical expansion have put the focus on the emerging
nature of RVF. Notably, the epidemiological aspects of
RVF, which include ecology, environment, knowledge,
practices, and both animal and human health, emphasize
the necessity of a One Health, One World approach (17).
This concept/approach implies that multidisciplinary
countermeasures in a global context have to be intro-
duced to ensure better environment, better food safety
and protection of human livelihood. In this context, it
is important to study how a RVF outbreak is affecting
different regions and countries.
RVF is a transboundary disease, which has an impact
on the important livestock trade between Sudan and
Saudi Arabia, separated only by the Red Sea, where Sudan
is the exporting and Saudi Arabia is the importing
country. The close economic links, the geographical prox-
imity of the two countries, and the two recent important
outbreaks of RVF in Saudi Arabia 2000 and Sudan (2007)
motivated us to investigate these outbreaks from a One
Health perspective. Specifically, we investigated the rea-
sons for, the consequences of, and countermeasures against
the outbreaks. The study revealed similarities and dis-
crepancies between the two countries regarding outbreak
causes, consequences, epidemiology of the disease, and
how the RVF outbreaks were tackled in terms of a One
Health approach at the human�animal interface.
MethodsUsing the terms ‘RVF’, ‘RVFV’, ‘Saudi Arabia’ and
‘Sudan’, 95 articles were identified by searching Medline
through PubMed (www.ncbi.nlm.nih.gov/sites/entrez) and
after reading their abstracts, 37 articles were found rele-
vant and included in this review. The books, reports,
and fact sheets that include information about the disease
were searched through the following sources: World
Health Organization (WHO) (www.who.int); World Orga-
nization of Animal Health (OIE) (www.oie.int); Food and
Agriculture Organization of the United Nations (FAO)
(www.fao.org); Saudi Arabia Ministry of Health, Google
scholar; and United States Center for Emerging Issues
(www.aphis.usda.gov).
Results
Outbreak and consequencesSaudi Arabia
Saudi Arabia experienced a large RVF outbreak in the
year 2000. It was the first outbreak in this country and the
first outside Africa. The first reports on animal disease,
reminiscent of RVF, were in August and early Septem-
ber with widespread abortions in sheep and goats (18).
The appearance of RVF in ruminants was in some cases
dramatic with 60�90% abortions in pregnant animals
within a period of 10�14 days (18). In dryer zones in the
north, only 5�20% of the pregnant animals were affected
(18). During these first days of the outbreak, 2,699
abortions and 943 deaths were recorded in the animals
(18). It was later estimated that during the outbreak
around 40,000 animals died such as sheep, goats, camels,
and cattle and 8,000�10,000 of them were aborted (19).
Human cases with RVF was reported in Saudi Arabia
for the first time in September 10, 2000 (20), when the
Ministry of Health in Saudi Arabia asked for help to
investigate unexplained human hemorrhagic fever cases
reported from the health care centers of the western bor-
der in association with animal deaths. The serum samples
of the suspected human and animal cases were confirmed
to be RVF by the United States Centre for Disease
Control and Prevention (CDC) 5 days later. In total, the
outbreak lasted for about 7 months and 883 human cases
were recorded, with 124 deaths (case fatality rate, 14%) in
Saudi Arabia (3) and an additional 1,328 human cases,
with 166 deaths, were concurrently recorded in neighbor-
ing northwestern Yemen (21�23). After the outbreak
was declared, a team was established in collaboration
between the Ministries of Health, Agriculture and Water,
and the Ministry of Municipalities and international
organizations such as CDC, WHO, and National Insti-
tute of Virology, South Africa, to control the outbreak
(2, 20, 22).
The area first affected by the disease was Jizan province
with pockets of the disease in Asir and Alqunfdah (Fig. 1).
The majority of animal cases were in the Jizan region
(66%), with 27% in Tahamat Asir and 7.5% in Tahamat
Makkah (23). The seroprevalence in humans was 47% in
Jizan, 48% in Asir, and 4% in Alqunfdah (20, 21) (Fig. 1).
Jizan province is located in the south west of the country
near the coast of the Red Sea bordering Yemen where
an outbreak occurred simultaneously, and also for the
first time (20, 21). The RVF outbreak in Saudi Arabia
started in the western part, with the largest impact in
the Jizan region. This could be the result of an amplifica-
tion of an already previously introduced virus when the
conditions were favorable for transmission (24). The
outbreak region of Jizan and the surrounding area was
located in the valley called Tihama Wadi, which covers
most of the coastal plain of Saudi Arabia in the south-
western area. The rainfall in the surrounding mountains is
transported by seasonal water to these plains (18) and has
encouraged the people to reclaim the land for cultivation
with the use of traditional irrigation canals (18). In 2000,
there was a rainier season compared to the normal annual
rainfall in this area (25).
Osama Ahmed Hassan et al.
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Sudan
The Sudanese outbreak in 2007 followed unusually heavy
rains resulting in severe floods (26). The first human
RVF cases appeared at the beginning of September 2007
(16, 27). Then, in October 18 2007, the Federal Ministry
of Health (FMoH) Sudan asked the WHO to assist in
the investigation and control of a suspected hemorrhagic
fever outbreak and after analysis of human patient sam-
ples, an RVF outbreak was declared 10 days later (14).
Two weeks later, the Sudanese Ministry of Animal
Resources and Fisheries informed OIE that positive cases
of RVF had been found in cattle and sheep at the end of
October in White Nile state at the same place where
human cases were reported (28, 29). Later, RVFV positive
goats were detected (30). A task force from FMoH and
Federal Ministry of Animal resources and fisheries
started to deal with the outbreak with assistance from
the Eastern Mediterranean Regional Office of WHO in
terms of technical support (31). The outbreak lasted until
January 2008. During the outbreak, 698 human cases of
RVF were recognized with 222 deaths (case fatality rate:
31.5%) (32). No records of the total number of cases in
animals are available.
The most severely affected areas were three agricultural
states in central Sudan near the White Nile and the Blue
Nile (White Nile, Sennar, Gazira) (Fig. 1) (31). Interest-
ingly, the virus was detected here already in 1973 during
a previous RVF outbreak close to Kosti in the White
Nile state (Fig. 1) (33). It has been suggested that infec-
ted animals passing Gazira state introduced and caused
the outbreak close to Wad Madani on their way to
Khartoum or to Port Sudan in the northeast (24, 34).
According to WHO, the majority of the human cases
were seen in Gazira (28), an area with agriculture and
irrigation canals. Many RVF cases were also detected
in Khartoum, but it was suggested that patients were
infected in rural areas (35).
Strategies for controlOperationalization of One Health in Saudi Arabia
After the outbreak was declared in Saudi Arabia, control
measurements were simultaneously implemented toward
Fig. 1. Map of Sudan and Saudia Arabia. RVF outbreak areas are indicated in red, irrigation and/or areas with seasonal water are in
blue, and agricultural states in green.
One Health approach to Rift Valley fever
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both humans and animals. Surveillance was urgently
introduced to detect cases of RVF among ungulates and
humans. Dead animals were disposed of in an appro-
priate manner (2, 22). A survey among animals was also
conducted to locate target areas for animal vaccination
and then apply a vaccination campaign that started in
October 2000 (19, 20, 23). Around 1,200,000 doses of
vaccine were reported to be imported to Saudi Arabia
and the campaign continued during 2001 with more than
10 million ruminants being vaccinated (23). This was ac-
companied by a restriction on animal movements outside
the affected areas and a ban on animal imports from
RVF-enzootic countries (21). For human health, a
detailed case definition was described and distributed to
all health providers by the Saudi Ministry of Health (21).
Two laboratories (one in the affected regions and the
other in the capital of the country) were well prepared for
diagnosis of RVFV antibodies in suspected cases (2).
Epidemiological investigation was performed to identify
risk factors (22). Furthermore, training sessions were held
to inform medical health providers on how to manage the
suspected cases clinically (20). In addition, an entomolo-
gical study to search for the mosquito breeding grounds
(22) was followed by an intensive mosquito control
program with spraying (20, 36). The One Health strategy
implemented by Saudi Arabia on both the animal and
human side succeeded to limit the effect of the outbreak
and curb the disease to the onset area of the Gizan
region. Only sporadic cases have been recorded in
Saudi Arabia since the outbreak and only in the same
regions as the original outbreak (19). It is difficult to rate
the effect of the control measures, and it is rather the
integrated control measures that were successful.
Operationalization of One Health in Sudan
As soon as outbreak was announced, the governors of
the affected states formed a committee to deal with the
outbreak. The committee aimed to reflect a One Health
strategy to tackle the disease outbreak. The committee
was led by the general director of the government in
the affected states and consisted of members from the
ministry of Health, ministry of animal resources and a
consortium of consultants, including community medi-
cine, internal medicine, ophthalmology, nephrology, and
pharmacology.
For control of the RVF outbreak in Sudan, the
committee aimed to target both human and animal
health. To minimize the risk of transmission in slaughter-
houses, strong precautions were applied (37). Unfortu-
nately, no information was available about how dead
animals were disposed of. Restrictions of animal move-
ment were introduced. Normally, the system of pasture in
Sudan includes free movement of herds over large
distances. To assess the situation, surveillance of animal
cases in the most affected states (Gazira, Sennar, and
White Nile) was performed (38, 39). Vaccination of
animals at high risk was implemented at the later stages
of the outbreak in other states, such as Upper Nile state,
south of White Nile state (37�39). To control the vectors,
insecticides were used among animals and in the environ-
ment (38, 39). Active surveillance was initiated to find
human cases as quickly as possible. Moreover, public
health actions such as social mobilization of the society
were implemented (26�28). NGOs were involved in health
promotion and volunteers from the local communities
were trained to be a part of the health promotion against
the disease. There was an attempt to enhance the
diagnostic capacity in terms of trained technicians and
availability of laboratory supplies to detect the cases (28).
Although Sudan aimed to implement a One Health
strategy as mentioned above, it did not restrict the disease
to the onset region in White Nile state. It spread to the
states of Gazira, Sennar, and Kassala. The difference regard-
ing the implementation of One Health in Sudan and
Saudi Arabia is intriguing and possibly reflects the
difference in resources.
Discussion
Virus transmissionThe RVF outbreaks were unexpected and caused great
commotion in both Saudi Arabia and Sudan. No RVF
outbreaks had been recognized for more than 30 years in
Sudan and RVF had never been present in Saudi Arabia.
The transmission to Saudi Arabia is suggested to be from
Eastern Africa by importation of infected animals (40),
similar to the suggested route of introduction of RVFV
to Egypt in 1977 from Sudan (41). The virus causing
the Saudi Arabia outbreak belonged to the same strain
that caused the 1997�98 outbreak in the African Horn
(42) and the virus could either have been a previously
unrecognized introduction (43) followed by virus ende-
micity in the Wadi zones for some years in cryptic foci
(19) or a very recent transmission. As mentioned above,
Sudan has a history of RVF outbreaks although no major
outbreaks have been reported for a long period. Similar
to Saudi Arabia, the outbreak in Sudan could have been
caused by an enzootic virus present for a long time
(33, 44) or it could have been an introduction of RVFV
from the large outbreak in Kenya, Somalia, and Tanzania
in 2006�07 that preceded the Sudan outbreak. Recently,
sequencing of RVFV strains from the 2007 outbreak in-
dicated that genetic RVFV variants circulating in Sudan
were all related to sublineages from the 2006�07 eastern
Africa epizootic (45). However, the sequencing suggested
an earlier common ancestor from 1996 (45) coinciding
with the 1997�98 outbreak in the African Horn (42), so
multiple introductions are likely (45).
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Climatic and ecological aspectsIn Sudan, the outbreak was triggered by severe flooding
(26) as a result of El Nino conditions and increasing
surface temperature of the eastern Pacific Ocean (24).
This climatic condition also affected Kenya, Tanzania,
and Somalia during the 2006�07 outbreaks (24). This
extreme weather was important but most probably not
the only reason, because such weather has occurred
before in Sudan without any documented outbreaks. In
Saudi Arabia, the outbreak coincided with heavy rains in
the affected and surrounding areas (18). The area of most
interest in terms of rainfall patterns could be the mountain
catchment areas that feed the Wadi that constitute the
alluvial floodplains in the region (18). This mountain area
had extensive rains during the 2000 rainy season, filling
swamps and wetlands during 2000, which could provide
good conditions for mosquito breeding (18). Such an area
is the Tihama Wadi in Saudi Arabia where many irrigation
canals are present (15). For Sudan, remote sensing of
environmental factors predicted that conditions likely to
lead to an RVF outbreak were found 3 months before
the outbreak (24). The prediction was generalized and did
not take into account regional differences, which resulted
in an overall performance of 50% of the human cases
mapped to the correct locations (24). This indicates the
need for higher resolution models (24, 34). The ecology of
the area could be more or less suitable for an outbreak to
occur. In Sudan, agricultural areas around the tributaries
of the Nile, such as Gazira, were affected by the outbreak
while the Saudi affected areas were near the coast of
the Red Sea, connected to irrigation farming (Fig. 1). The
ecology and environment in the affected regions of the
two countries were similar providing an attractive habitat
for the mosquito vectors to multiply, similar to the
Ifakarra rice valley in Tanzania and the highlands of
Madagascar (24). Large-scale modifications of the envi-
ronment could also lead to better conditions for RVFV
vectors. The first outbreak of RVF in Egypt in 1977 was
triggered by the construction of the Aswan dam on the
Nile River, starting mosquito breeding in newly flooded
areas. In 1987, the Mauritanian RVF outbreak was caused
by flooding after the Diama dam construction in the
Senegal River, which later led to the spread of RVF in
Mauritania (46, 47). It is worth mentioning that a new
large dam was recently constructed in Merowe on the
Nile river basin in north Sudan. Around this area there
was serological evidence of RVFV in the 80s (48). A
future scenario could be similar to the scenario in
Egypt 1977 where an outbreak occurred 6 years after the
Aswan dam construction (46). Thus, surveillance of
animals and mosquitoes around the dam is needed in
order to detect the presence of RVFV as early as possible
in order to disrupt any future outbreak in this area of
the country.
Vector competence and animal reservoirDuring the outbreaks most efforts were directed toward
acute control measures, but later, studies regarding
vector competence of the RVFV were performed in Saudi
Arabia (25). The result of these studies was important
for later control and surveillance of mosquitoes for new
RVF outbreaks (40). In Sudan, the role of vectors was
only partially studied and only at the later stages of the
outbreak (27). This weakens control efforts for future
outbreaks and leaves the local epidemiology of the disease
unclear. In the two countries the disease was restricted
to rural areas. However, in Sudan the virus was also
identified from some species of mosquitoes in Khartoum
(27). It is unknown if the virus could be established and
circulate in densely populated urban areas where surveil-
lance should be considered in the future. In general,
studies need to be implemented to identify RVF com-
petent vectors at the country level. The better the under-
standing of the vectors and their preferred animal hosts,
the more efficient and cost-effective the prevention and
control programs. Cattle, sheep, and goats were affected
in the outbreak in the two countries but other animals,
such as rats, camels, and donkeys (49), could also be
involved in the virus transmission cycle. The most severe
form of the disease is usually found in animals of
European origin, rather than local ones (14). More
information about the breeds involved in the outbreaks
will lead to a better understanding of the disease
epidemiology and consequently facilitate proper preven-
tion and control of the disease.
The role of surveillance systems in detectingthe RVF outbreaksSaudi Arabia and Sudan are large countries with several
neighboring countries. Shared borders might increase the
risk of spreading RVF unless great care is taken regarding
trade regulation of animals in the region. Application to
regulations and guidelines from the World Trade Orga-
nization and OIE would reduce the danger of RVF
being introduced to new unaffected countries. For both
Saudi Arabia and Sudan, the surveillance system did not
work properly to detect the virus in animals before it
spread to humans, although it has been suggested that
RVF is well established in animals before any disease
outbreak in humans (50). In Saudi Arabia, disease occur-
rence in humans was reported in association with animal
deaths while in Sudan the animal cases were discovered
later. The period between the onset of an unknown febrile
illness among humans and the confirmation of a RVF
outbreak was 18 days in Saudi Arabia, while it took three
times longer in Sudan (14, 20, 21). This discrepancy
probably reflects the lack of data management and
communication between the regional and federal health
authorities in Sudan.
One Health approach to Rift Valley fever
Citation: Infection Ecology and Epidemiology 2014, 4: 20710 - http://dx.doi.org/10.3402/iee.v4.20710 5(page number not for citation purpose)
The outbreak in Saudi Arabia 2000 lasted for a longer
time than in Sudan but with almost half the case fatality
rate compared to Sudan. The stronger economy and the
better capacity, contingency plans, and health care system
in Saudi Arabia were probably the main factors for the
lower fatality rate. One could suspect that there were
more undiagnosed cases and late recognition of RVF
cases in Sudan compared to Saudi Arabia, which could
explain the higher case fatality rates associated with the
human cases in Sudan. A similar experience of late
diagnosis was seen in other RVF outbreaks, for example
in Kenya in 1997�98 where 467 unexplained deaths
occurred in humans before it was discovered that it was
caused by RVF (51). In general, the recognition of human
and animal cases needs good communication and colla-
boration between veterinary and health authorities to
gather the epidemiological features of a zoonotic out-
break. In particular, surveillance and prediction models
of imminent outbreaks could be improved by collecting
data such as animal and human sera as well mosquitoes
from high-risk RVF sites during interepidemic periods to
detect virus activity as early as possible (52). At later
stages of the outbreak in Saudi Arabia, results from
studies undertaken earlier regarding risk factors were
used in the health education messages and led to a reduc-
tion in morbidity. However, in Sudan the risk factors were
not studied in detail, which probably led to a less cost-
effective control strategy.
To advocate for surveillance in RVF endemic regions
among affected countries, we have to think seriously to
compensate the communities that are exposed to RVF
outbreaks to enable them to recover from their economic
losses. After verification of RVF cases by veterinary
authorities and community leaders, compensation could,
for instance, be in the form of replacing dead or sick
animals with new animals, and vaccination against all
vaccine preventable diseases including RVF. Part of the
support should also be directed toward improving the
infrastructure of the veterinary facilities in the affected
areas. This support could be offered by the government
of the affected country if its economy allows that. In
addition, the neighboring countries could also contribute
because they are also in danger when the disease expands.
Furthermore, regional and international organizations
should contribute to such a compensation program. It
would also be beneficial if regional funds were set aside
to use for combating emerging infectious diseases includ-
ing RVF. Altogether, such actions would encourage local
communities and governments to notify authorities ear-
lier about the circulation of RVF in their countries.
One Health economics of RVFIn Sudan, livestock is one of the most important con-
tributors to the national economy. It employs around
40% of the population and contributes to 25% of the
gross domestic product (GDP) (53). Before the RVF
outbreak, Sudan’s share of the total sheep trade in the
world was 10% and the main export market was Saudi
Arabia (54). Both the domestic and international animal
market of the country has a huge economic impact. This
was clearly demonstrated during the ban of animal trade
from November 2007 to August 2008. Since most of the
export animals came from the rural areas of Sudan, one
could expect the ban to have the most severe impact on
rural households and the rural economy. Unfortunately,
no studies have been undertaken to explore that. The
disease killed and caused abortions in many animals such
as sheep and goats. They are an important source of food,
milk, and meat, and this animal trading brings money
into the rural communities in the affected regions. In
Saudi Arabia, the estimated direct and indirect losses
due to the RVF outbreak reached US $75�90 million in
1 year (19, 36). After the outbreak, the ban on importing
animals from Eastern Africa disrupted the trade of live
animals in the country. This trade is relevant to the
religious festival events of Muslims in Mecca, Saudi
Arabia, and it is estimated to be worth US $ 600�900
million annually. The impact was on both the demand
side of Saudi Arabia and the main supplying countries
in East Africa, including Sudan (54). Thus, the RVF
outbreaks point to the severe consequences involved in
disrupting the animal trade economy and the current
lack of information regarding the economic impact of
RVF at the macro- and microeconomic level. Because the
outbreaks are first recognized at the local level, it is
important to ensure cooperation with local communities
for prevention and control efforts at an early stage.
Therefore, studies regarding the social consequences of
RVF outbreaks for rural communities and qualitative
studies to investigate the knowledge and attitudes toward
the disease are needed.
Because animals, humans, and the environment are all
involved in the infection cycle of RVFV, we expect that
the budgets of ministries representing these interests
are compiled together to prioritize control strategies
against RVF. Such an initiative has not been visible in
Saudi Arabia or Sudan.
ConclusionsHuman and animal health is a result of the sustainable
relationship between humans, animals, and the environ-
ment. Therefore, it is important to tackle health problems
in animals to protect human health. To prevent future
RVF outbreaks, information based on virologic, epide-
miologic, and demographic data; surveillance; and a
better understanding of environmental factors and the
ecology of RVFV are required to fine-tune existing
approaches that could predict an outbreak. The impact
of climate change on the spread and expansion of the
disease needs to be studied in detail in order to adapt
Osama Ahmed Hassan et al.
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Citation: Infection Ecology and Epidemiology 2014, 4: 20710 - http://dx.doi.org/10.3402/iee.v4.20710
mitigation strategies. To achieve the goal of One Health,
good collaboration between international organizations
on a planning level as well as veterinary and health au-
thorities on the executive level in each country is needed;
this could reduce the occurrence of RVF in Sudan,
Saudi Arabia, and other countries where the disease
could emerge.
Acknowledgements
The study was supported by the Swedish International Development
Cooperation Agency, the Swedish Research Council, the Medical
Faculty of Umea University, and the County Council of Vaster-
botten. The first author (OAH) was supported by a Global Health
Research Scholarship from Umea University.
Conflict of interest and fundingThe authors have not received any funding or benefits
from industry or elsewhere to conduct this study.
References
1. Pepin M, Bouloy M, Bird BH, Kemp A, Paweska J. Rift Valley
fever virus (Bunyaviridae: Phlebovirus): an update on patho-
genesis, molecular epidemiology, vectors, diagnostics and pre-
vention. Vet Res 2010; 41: 61.
2. World Health Organization. Outbreak news. Rift Valley fever
in Saudi Arabia. Available from: http://www.who.int/csr/don/
2000_09_29/en/index.html [cited 10 December 2012].
3. Balkhy HH, Memish ZA. Rift Valley fever: an uninvited
zoonosis in the Arabian peninsula. Int J Antimicrob Agents
2003; 21: 153�7.
4. Gerdes GH. Rift Valley fever. Rev Sci Tech 2004; 23: 613�23.
5. House JA, Turell MJ, Mebus CA. Rift Valley fever: present
status and risk to the Western Hemisphere. Ann N Y Acad Sci
1992; 653: 233�42.
6. Chevalier V, Pepin M, Plee L, Lancelot R. Rift Valley fever � a
threat for Europe? Euro Surveill 2010; 15: 19506.
7. Weaver SC, Reisen WK. Present and future arboviral threats.
Antiviral Res 2010; 85: 328�45.
8. Food and Agriculture Organization of the United Nations.
Preparation of Rift Valley fever Contingency plans. Rome: FAO
Animal Health Manual 2003; 15: 25�8.
9. Martin V, Chevalier V, Ceccato P, Anyamba A, De Simone L,
Lubroth J, et al. The impact of climate change on the
epidemiology and control of Rift Valley fever. Rev Sci Tech
2008; 27: 413�26.
10. Pfeffer M, Dobler G. Emergence of zoonotic arboviruses by
animal trade and migration. Parasit Vectors 2010; 3: 35.
11. World Health Organization. Rift Valley fever factsheet no 207.
Available from: http://www.who.int/mediacentre/factsheets/
fs207/en/index.html [cited 20 December 2011].
12. Madani TA, Al-Mazrou YY, Al-Jeffri MH, Mishkhas AA, Al-
Rabeah AM, Turkistani AM, et al. Rift Valley fever epidemic
in Saudi Arabia: epidemiological, clinical, and laboratory
characteristics. Clin Infect Dis 2003; 37: 1084�92.
13. Nguku PM, Sharif SK, Mutonga D, Amwayi S, Omolo J,
Mohammed O, et al. An investigation of a major outbreak of
Rift Valley fever in Kenya: 2006�2007. Am J Trop Med Hyg
2010; 83: 5�13.
14. Hassan OA, Ahlm C, Sang R, Evander M. The 2007 Rift Valley
fever outbreak in Sudan. PLoS Negl Trop Dis 2011; 5: e1229.
15. Al-Hazmi M, Ayoola EA, Abdurrahman M, Banzal S, Ashraf
G, El-Bushra A, et al. Epidemic Rift Valley fever in
Saudi Arabia: a clinical study of severe Illness in humans. Clin
Infect Dis 2003; 36: 245�52.
16. El Imam M, Elsabig M, Omran M, Abdalkareem A, Muhamadani
A, Mohamed E, et al. Acute renal failure associate with Rift
valley fever: a single center study. Saudi J Kidney Dis Transpl
2009; 20: 1047�52.
17. Dehove A. One World, One Health. Transbound Emerg Dis
2010; 57: 3�6.
18. EMPRES. Transboundary Animal Diseases Bulletin: 2000; 15:
4�9. FAO corporate document repository. http://www.fao.org/
docrep/003/X9550E/X9550E00.HTM
19. Al-Afaleq AI, Hussein MF. The status of Rift Valley fever in
animals in Saudi Arabia: a mini review. Vector Borne Zoonotic
Dis 2011; 11: 1513�20.
20. United States Centers for Disease Control and Prevention
(CDC). Outbreak of Rift Valley fever � Saudi Arabia, August�October, 2000. Morb Mortal Wkly Rep 2000; 49: 905�8.
21. Saudi Ministry of Health. Department of Preventive Medicine
and Field Epidemiology Training Program. Rift Valley Fever
outbreak, Saudi Arabia, 2000. Saudi Epidemiol Bull 2001; 8:
1�8.
22. United States Centers for Disease Control and Prevention
(CDC). Update: outbreak of Rift Valley fever � Saudi Arabia,
August�November, 2000. Morb Mortal Wkly Rep 2000; 49:
982�85.
23. Elfadil AA, Hasab-Allah KA, Dafa-Allah OM. Factors asso-
ciated with Rift Valley fever in South-West Saudi Arabia. Rev
Sci Tech 2006; 25: 1137�45.
24. Anyamba A, Linthicum KJ, Small J, Britch SC, Pak E,
de La Rocque S, et al. Prediction, assessment of the Rift Valley
fever activity in East and Southern Africa 2006�2008 and
possible vector control strategies. Am J Trop Med Hyg 2010;
83(2 Suppl): 43�51.
25. Jupp PG, Kemp A, Grobbelaar A, Leman P, Burt FJ, Alahmed
AM, et al. The 2000 epidemic of Rift Valley fever in
Saudi Arabia: mosquito vector study. Med Vet Entomol 2002;
16: 245�52.
26. Moszynski P. Flooding worsens in Sudan. BMJ 2007; 335: 175.
27. Seufi AM, Galal FH. Role of Culex and Anopheles mosquito
species as potential vector of Rift Valley fever virus in Sudan
outbreak, 2007. BMC Infect Dis 2010; 10: 65.
28. World Health Organization. Outbreak news, Report update
2: Rift Valley fever in Sudan. http://www.who.int/csr/don/
2007_11_14/en/index.html [cited 14 January 2013].
29. United States Department of Agriculture. Info sheet: Summary
of Selected disease events October�December 2007. Rift Valley
fever (RVF), Sudan. APHIS Veterinary services. Centers for
Epidemiology and Animal Health. January 2008; 2�3. Available
from: http://www.aphis.usda.gov/animal_health/emergingissues/
downloads/Q42007.pdf [cited 14 January 2013].
30. World Organization of Animal Health (OIE), World Animal
Information Database. Rift Valley fever in Sudan. Follow-up
report No. 2, Dec 2007. Report reference: OIE Ref: 6637,
Report Date: 30/12/2007, Country: Sudan. Available from:
http://www.oie.int/wahis_2/temp/reports/en_fup_0000006637_
20071230_150248.pdf [cited 10 December 2012].
31. Cooke FJ, Shapiro DS. Rift Valley fever in Sudan. Int J Infect
Dis 2008; 12: 1�2.
32. World Health Organization. Outbreak news: Report update 5:
Rift Valley fever in Sudan. Available from: http://www.who.int/
csr/don/2008_01_22/en/index.html [cited 14 January 2013].
33. Eisa M, Kheer, El Sid ED, Shomein AM, Meegan JM. An
outbreak of Rift Valley fever in the Sudan-1976, Trans R Soc
Trop Med Hyg 1980; 74: 417�18.
One Health approach to Rift Valley fever
Citation: Infection Ecology and Epidemiology 2014, 4: 20710 - http://dx.doi.org/10.3402/iee.v4.20710 7(page number not for citation purpose)
34. FAO�WHO Experts Consultation. Rift Valley fever outbreaks
forecasting model. GAR publications, Rome, Italy; 2009, pp.
4�6. Available from: www.who.int/csr/resources/publications
[cited 22 January 2013].
35. World Health Organization. Outbreak news: report update 3:
Rift Valley fever in Sudan. Available from: http://www.who.int/
csr/don/2007_11_22/en/index.html [cited 22 January 2013].
36. Shimshony A, Economides P. Disease prevention and prepared-
ness for animal health in the Middle East. Rev Sci Tech 2006;
25: 253�69.
37. Food and Agriculture Organization of the United Nations. FAO
assists Sudan in controlling Rift Valley fever. FAO Newsroom.
Available from: http://www.fao.org/newsroom/en/news/2007/
1000703/index.html [cited 9 November 2012].
38. World Organization of Animal Health (OIE), World Animal
Information Database. Rift Valley fever in Sudan. Follow-up re-
port No. 1, Nov 2007. Report reference: OIE Ref: 6495, Report
Date: 21/11/2007, Country: Sudan. Available from: http://
www.oie.int/wahis_2/temp/reports/en_fup_0000006495_20071121_
180110.pdf [cited 10 December 2011].
39. World Organization of Animal Health (OIE), World Animal
Information Database. Rift Valley fever in Sudan. Follow-up
report No. 4, November 2008. Report reference: OIE Ref: 7523,
Report Date: 14/11/2008, Country: Sudan. Available from:
http://www.oie.int/wahis_2/temp/reports/en_fup_0000007523_
20081114_180721.pdf [cited 14 February 2012].
40. Miller BR, Godsey MS, Crabtree MB, Savage HM, Al-Mazrao
Y, Al-Jefrri MH, et al. Isolation and genetic characterization of
Rift Valley fever virus from Aedes vexans arabiensis, Kingdom
of Saudi Arabia. Emerg Infect Dis 2002; 8: 1492�4.
41. Gad AM, Feinsod FM, Allam IH, Eisa M, Hassan AN,
Soliman BA, et al. A possible route for the introduction of
Rift Valley fever virus into Egypt during 1977. Am J Trop Med
Hyg 1986; 89: 233�6.
42. Shoemaker T, Boulianne C, Vincent MJ, Pezzanite L, Al-
Qahtani MM, Al-Mazrou Y, et al. Genetic analysis of viruses
associated with emergence of Rift Valley fever in Saudi Arabia
and Yemen, 2000�01. Emerg Infect Dis 2002; 8: 1415�20.
43. Turkistany AH, Mohamed AG, Al-Hamdan N. Seroprevalence
of Rift Valley fever among slaughterhouse personnel in Makkah
during Hajj 1419 (1999). J Family Community Med 2001; 8:
53�7.
44. Findlay GJ, Stefanopoulo GM, Mac Callum F. Presence
d’anticorps contre la fievre de la vallee du Rift dans le sang
des africains. Bull Soc Pathol Exot 1936; 29: 986�96.
45. Aradaib IE, Erickson BR, Elageb RM, Khristova ML, Carroll
SA, Elkhidir IM, et al. Rift Valley fever Sudan, 2007 and 2010.
Emerg Infect Dis 2013; 19: 246�53.
46. Wilson ML. Rift Valley fever virus ecology and the epidemio-
logy of disease emergence. Ann N Y Acad Sci 1994; 740: 169�80.
47. Digoutte JP, Peters CJ. General aspects of the 1987 Rift Valley
fever epidemic in Mauritania. Res Virol 1989; 140: 27�30.
48. Watts DM, el-Tigani A, Botros BA, Salib AW, Olson JG,
McCarthy M, et al. Arthropod-borne viral infections associated
with a fever outbreak in the northern province of Sudan. J Trop
Med Hyg 1994; 97: 228�30.
49. Youssef BZ, Abo-Donia H. The potential role of Rattus rattus
in enzootic cycle of Rift Valley fever in Egypt. II-Application
of reverse transcriptase polymerase chain reaction (RT-PCR)
in blood samples of Rattus rattus. J Egypt Publ Health Assoc
2001; 77: 133�41.
50. Munyua P, Murithi RM, Wainwright S, Githinji J, Hightower
A, Mutonga D, et al. Rift Valley fever outbreak in livestock in
Kenya, 2006�2007. Am J Trop Med Hyg 2010; 83: 58�64.
51. United States Centers for Disease Control and Prevention
(CDC). Rift Valley fever-East Africa, 1997�1998. Morb Mortal
Wkly Rep 1998; 47: 261�4.
52. Breiman RF, Njenga MK, Cleaveland S, Sharif SK, Mbabu M,
King L. Lessons learned from the 2006�7 Rift Valley fever
outbreak in East Africa: implications for prevention of emerging
infectious diseases. Future Virol 2008; 3: 411�7.
53. El Dirani OH, Jabbar MA, Babiker BI (2009). Constrains in the
market chains for export of Sudanese sheep and sheep meat to
the Middle East. Report research 16. ILRI publication unit,
Addis Ababa, Ethiopia: International Research Institute (ILRI),
p. 8.
54. The Integrated Framework Program. Revitalizing Sudan’s non-
oil exports: a diagnostic trade integration study; 2008; 41�115.
*Magnus EvanderDepartment of Clinical MicrobiologyDivision of VirologyUmea UniversityS-901 85 UmeaSwedenEmail: [email protected]
Osama Ahmed Hassan et al.
8(page number not for citation purpose)
Citation: Infection Ecology and Epidemiology 2014, 4: 20710 - http://dx.doi.org/10.3402/iee.v4.20710
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